Histology Md1 Block 2 Muscular Tissue Part 2

Front 1

Classification of muscle fibers

is dominated by type I fibers

Back 1

Red muscle (red meat)

Fast or slow twitch

Hint 1

slow-twitch

high-oxidative fibers


small diameters, much myoglobin, many well-developed mitochondria, a rich blood supply
high metabolic activity involved in slow sustained contractions e.g. for maintenance of posture
soleus muscle in calf of leg
energy source is from oxidative phosphorylation.

Front 2

Classification of muscle fibers

is dominated by type IIa fibers.

Back 2

White fibers

Hint 2

fast-twitch glycolytic-anaerobic fibers


These have larger diameters, less myoglobin and fewer mitochondria, relatively poorer blood supplies.
These type IIa fibers are involved in rapid contraction (fast twitch) with anaerobic glycolysis.

Front 3

Classification of muscle fibers

White muscle (white meat)

Back 3

Type 2

Front 4

Classification of muscle fibers

to histochemical techniques for enzymatic activities =
2ct

Back 4

succinic dehydrogenase activities (localized in mitochondria)
ATP-ase activities

Front 5

Know slide #17 entire table but deduction should work well

Back 5

.

Front 6

Alpha Actinin in which Myo-Band =

Back 6

Z Line

Front 7

major protein of the M line is =

Back 7

creatine kinase.

info

Hint 7

The major protein of the M line is creatine kinase. Creatine kinase catalyzes the transfer of a phosphate group from phosphocreatine (a storage form of high-energy phosphate groups) to adenosine diphosphate (ADP), thus supplying adenosine triphosphate (ATP) for muscle contraction.

Front 8

Molecular components of the myofilaments

The myofilaments are composed of four main molecules:
4ct

Back 8

myosin
actin,
tropomyosin
troponin

Front 9

is a long polypeptide molecule and to which are attached to actin molecules (like a string of pearls).

Back 9

Tropomyosin

Front 10

Thin myofilaments

The thin myofilaments are composed of two tropomyosin molecules with attached

Back 10

attached actin and troponin in a double helix (supported by nebulin).

Front 11

Thin myofilaments

The troponin molecule is organized into specific regions:

Back 11

TnT, which binds to tropomyosin
TnC, which binds to calcium
TnI, which in involved in inhibiting the actin-myosin interaction.

Front 12

Thin myofilaments

Two types of actin are found:

Back 12

G-actin (globular) consists of spherical monomers of about 5.6nm diameter. The monomers are polarized, with one hemisphere having specific binding sites for myosin.

F-actin (fibrous) consists of chains or strings of G-actin molecules.

Front 13

TiTan Molecule does what =

Back 13

Rebound job after contraction

Front 14

Sarcoplasmic Reticulum & Transverse Tubule System

Back 14

.

Front 15

Each sarcomere has two of these tubules.

Back 15

T-tubules (transverse tubules)

Front 16

are sites of accumulation of calcium ions

Back 16

terminal cisternae

info

Hint 16

The sarcoplasmic reticulum is a network of sarcotubules surrounding each myofibril. Swollen terminal cisternae or sacs of the sarcoplasmic reticulum are associated with the T-tubules.

Two terminal cisternae are associated with each T-tubule to form structures (visible by transmission electron microscopy) known as triads.

The membranes of the terminal cisternae are connected with the T-tubules by gap junctions.

These terminal cisternae are sites of accumulation of calcium ions during muscle relaxation and play an important role in the contraction process.

Front 17

Each myofiber is innervated by

Back 17

efferent nerve impulses from axon terminals of motor end plates.

Front 18

Afferent means

Back 18

Aff

Arriving

h+

Hint 18

Brain
alwaysarriving to the brain
Brain is the definitional Hub

Front 19

Efferent mens

Back 19

EFF
exit

H+

Hint 19

Brain
always exits the brain
Brain is the definitional Hub